Martinez (9-0) gave up one hit over five innings, striking out five batters and walking one. Foltynewicz, who had never pitched in relief before this season, yielded a single while fanning three the rest of the way for his third save.

At the start of the season, the Astros implemented the piggyback system, in which a starting pitcher throws five innings in one game, then comes out of the bullpen to throw four more a few days later. Corpus Christi leads the Texas League in wins (37) and shutouts (10) and is tied for second with a 3.58 ERA. Hooks right-hander Jake Buchanan leads the league with a 0.85 ERA and 0.76 WHIP, just ahead of Martinez (0.99).

Foltynewicz, who joined the team from Class A Advanced Lancaster at the beginning of May, is 1-0 with a 1.08 ERA and 33 strikeouts in 33 1/3 innings.

At this point, however, some on the pitching staff are looking forward to Corpus Christi following the lead of the Astros' Triple-A affiliate and opting for a more traditional approach.

"I mean, they said they don't know how long it's going to go. We're coming up on the All-Star break and it's wearing a little on us," Foltynewicz said. "One day you're pitching, then you have a day off, then a bullpen [session], then a day off, then you're working out of the bullpen. None of us are used to that and it's getting a little longer than any of us expected it to be. But we're making it work."

Martinez, who has a 2.35 ERA, was lifted after tossing five perfect innings on April 20. On Friday, he threw 49 of 73 pitches for strikes, faced three batters over the minimum and said he would have liked the opportunity to go deeper.

"I didn't want to come out after the fifth inning," the 25-year-old right-hander said through a translator. "I wanted to keep pitching, but I knew that they wouldn't have me pitch the sixth, and I understand that. For the most part, I just want to do my job."

Martinez has made his job look easy. After his last start, in which he surrendered seven runs -- five earned -- over 2 1/3 innings, he was determined to be his regular, reliable self against the RockHounds.

"Last time, I didn't feel all that good physically. I didn't have command of my fastball. I was leaving a lot of fastballs up," he said. "Everybody has a bad day every once in awhile and that's all it was, just a bad day. I tried to work in the bullpen on getting the ball back down, keeping the ball low in the zone. I went out there and that's exactly what happened -- I threw the ball down."

Martinez retired 10 of the first 11 batters before allowing a single in the fourth to Anthony Aliotti, who leads the league with a .352 batting average.

"I threw a two-seam instead of a four-seam fastball," he said. "It was still a good pitch, it just wasn't what I should have thrown. I wanted that pitch back."

Martinez struck out former Hook Jake Goebbert, then retired David Freitas on a ground ball to end the inning. After Dusty Coleman reached on a one-out error in the fifth, Martinez coaxed two more groundouts to end his evening.

"I'm really happy," the Venezuela native said. "This is the last year in my contract and I'm working hard, trying to do my job the best I can. And I'm happy with the results."

Foltynewicz said following Martinez's lead didn't affect his approach.

"We were up, 5-0, and I just wanted to keep that lead exactly where it was," he said. "Martinez has been pitching great this whole year, since before I got here, and I'm not going to put more pressure on myself than I need to. I just tried to go out and compete at my best."

Foltynewicz issued a leadoff walk to Conner Crumbliss, who was hit by a pitch in the eighth.

"When I faced him last time, he was tough. He is not a strikeout guy. He's a guy who's going to be patient," Foltynewicz said of the RockHounds' leadoff man. "The first time tonight, I felt a little weird, just nerves or something coming into the game. The next time, I spiked a slider. I tried to throw the slider a little harder, and it tailed more than I wanted it to. It slid into his front foot instead of around his back foot."

Foltynewicz worked around a leadoff walk in the seventh but has allowed only two unearned runs over 11 innings in his three save opportunities.

"Ever since we've had this piggyback thing, I guess there have been chances for saves," he said. "It's not really in my head, I just try to go out and do my best. It's not like I think, 'Oh, I've got to go out and get this save.' If I do my best, the saves or the wins or whatever will come."

Astros No. 3 prospect George Springer, batting leadoff for just the third time this season, delivered an RBI double and scored a run for the Hooks.

Josh Jackson is a contributor to MLB.com. This story was not subject to the approval of the National Association of Professional Baseball Leagues or its clubs.